?env:Netcgi_compat.Netcgi_env.cgi_environment ->
?processing:(string ->
             Netmime.mime_header -> Netcgi_compat.Netcgi.argument_processing) ->
?operating_type:Netcgi_compat.Netcgi.operating_type ->
unit -> Netcgi_compat.Netcgi_types.cgi_activation